obama is promising action. act >> we'll find out who did this,h and why they did any responsible individuals or groups will feel the full wait of justice. i think we have to be looking. >> it's al qaeda, off chute or a self starter in the united states, a homegrown terrorist. the search for bombing suspects likely includes an analysis of terror organizes worldwide.. the pakistani taliban denies any involvement in the marathonn explosion. the group's main focus is targeting the pakistani p government because of its alliance with the u.s.ance it has threatened attacks in thn u.s. before and says it was w behind a failed car bombing in times square in 2010. >> we want to keep you updated on metro which went on high alert following the bombings in boston. we speak with dan earlier today. he tells you security may be heightened. he stresses there's no specific threat against metro or any transit system. >> from the rails to the roads there an impact on drivers today because of emancipation dayion activities in the d